Respuesta :
Solution :
Quadrant IV ranges from 270 deg to 360 deg
Also sinθ = - value & cosθ= + value in IV quadrant
Here, sinθ = -1/2, we know sin30=1/2
this gives, θ = 330deg as sinθ = sin(360-θ)
Hence, cosθ=cos330=cos(360-30)=cos30
Answer: cos30 = âš3/2